WASHINGTON, Nov 22 (Reuters) - The U.S. Food and Drug Administration has approved the second human trial of human embryonic stem cells — this one testing cells in people with a progressive form of blindness, the company said on Monday.

It is the second trial of human embryonic stem cells to be approved by the FDA this year. Last month Geron Corp (GERN.O) enrolled the first patient in its study using the cells in people whose spinal cords have been crushed. [ID:nN11175966]

“It is exciting — a vindication. All this work really came through,” said Dr. Robert Lanza, chief medical officer of the company, which has struggled to stay solvent as it gambled on the controversial cells.

Stem cells are the body’s master cells, the source of all other cells. Proponents of using embryonic stem cells say the field could transform medicine, providing treatments for blindness, juvenile diabetes or severe injuries.

But opponents object because to get the cells, someone has to take apart a human embryo.

Last year the Obama administration overturned the strictest of the limitations on using federal funds for the research, but this summer, two researchers challenged the policy.

A U.S. appeals court has ruled that funding could continue while the government appeals, but grants from the National Institutes of Health have been frozen and unfrozen as various courts have weighed in. [ID:nN28118865]

Stargardt’s disease causes progressive vision loss, usually starting in children or young adults 10 to 20 years old, as eye tissue called the retinal pigment epithelium, or RPE, degenerates.

There is currently no treatment for the condition.

ACT has coaxed human embryonic stem cells into becoming RPE cells, which will be infused into patients’ eyes.

BOUNTIFUL SUPPLY

If all goes well with the Stargardt’s trial, Lanza says ACT has its eyes on a much larger potential market — macular degeneration.

Up to 30 million people in the United States and Europe have the blinding condition, which ACT sees as a potential $25 billion-$30 billion worldwide market.

Lanza said getting FDA approval for the trial was difficult. “They had us jumping through hoops,” he said.

This was in part because the powerful embryonic cells have the power to give rise to all cell types and can cause teratomas — strange tumors containing a mix of cells. Lanza said the company can find even a single cell that might do this and remove it from the treatment batch.

In addition, he said treating an eye disease offers the opportunity to watch the treatment.

“We can look into the eye in real time and see what is going on,” he said.

Research centers at the Oregon Health and Sciences University and University of Massachusetts will begin enrolling patients after their internal review boards approve the trial. “My guess is that we could start in as soon as two to three months,” Lanza said.